A system for controlling a commutation of a load current is provided. The
system comprises a AC-to-AC converter that includes a plurality of
switching elements, an energy source that provides an oscillating voltage
and is connected to the converter, an electrical load connected to the
converter, and a controller that controls the converter, and monitors the
oscillating voltage and the load current delivered to the electrical
load. The controller determines a plurality of machine states of the
converter, each of the plurality of machine states representing a
corresponding conducting set of the plurality of switching elements, and
controls switching between the plurality of machine states based on
polarity commutations of the load current in the electrical load and
polarity commutations of the oscillating voltage.